As is known, there are many situations in which it is necessary to walk, run or work on ground made slippery by rain, mud, snow and ice, or to pass such ground to dry ground covered with tarmac and hard and then back onto very slippery ground.
These ground conditions can affect the feet of an athlete, of a mountain climber, of an excursionist or of any person who works in these conditions every day.
Various types of shoe are currently known which are provided with soles with antislip tread for trekking, walking and safety.
It is also known that there are soles which constitute the tread directly, but there are also soles which, being made of materials which are not resistant to abrasion, have a tread which is applied to the lower part and is made of a different material which is more resistant to wear and to the stresses imparted by the forces involved during running or walking.
While antislip safety shoes are generally mostly provided simply with a sole with a tread which is grooved in a particular manner, trekking boots are also preset for fixing crampons to the sole.
Ordinary boots and rock-climbing boots are also known which are provided with crampons which can be extracted from the sole and retracted into it depending on whether one has to walk on ice or on a non-icy surface.
Said extractable crampons affect one or two limited regions of the sole and thus ensure grip only when at least one of said two regions, generally the toe and the heel, are pressed on the ground; further, in order to extract and retract the crampons it is necessary to act manually on the appropriately provided mechanism with which the sole is provided, interrupting the walk and crouching to manipulate the shoes on one's feet.
Further, the wearer of such shoes with soles provided with extractable crampons must realize in time that he/she is about to walk on icy ground and must act promptly to extract the crampons, otherwise the risks of falling are the same as with a pair of normal shoes.
Grip studs are also known which can be applied to any tread made of rubber or plastic material of any type of shoe; said studs can be removed easily from the anchoring seats, which are provided by screwing them into the tread, and subsequently reinstalled.
Although this series of studs ensures excellent grip on ice and rock, it requires considerable time for fitting and removal, and therefore the shoe prepared to deal with icy or generally slippery ground is very awkward to use on normal ground.
Further, screwing said very hard studs into the tread causes, if the tightening force is excessive, the tearing and cutting of the sole on the part of the threaded part of the stud, so that the stud is poorly positioned and does not work correctly but indeed flexes and tends to escape from the seat that has just been formed by the thread in the tread.
In a manner similar to what has been described for the soles of shoes, the treads of tires, even though they are grooved and temperature-adjusted, are well-suited for dealing with icy ground only with chains or studs.
Studded wheels are very awkward, since they have to be fitted as a replacement of ordinary wheels with a normal tread which is simply grooved, while snow chains are notoriously very awkward to fit, in addition to the fact that not all cars with high cylinder capacity can be fitted with such snow chains due to the proximity of the wheel to the wheelhouse that protects it.
Snow socks made of antislip fabric in which the wheel is wrapped are currently known as a replacement of snow chains.
Although these socks are easier to fit than chains and equally effective in terms of grip on ice, they too require a fitting operation and a removal operation in addition to occupying a certain volume in the trunk, like chains.